UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36

Steps to reproduce the problem:
1. open any page
2. click the right button of your mouse

What is the expected behavior?
The right-click context menu should be shown on mouseup

What went wrong?
The context menu is shown on mousedown

Did this work before? N/A 

Chrome version: 63.0.3239.132  Channel: stable
OS Version: OS X 10.12.6
Flash Version: 

I can't belivee that this issue was mentioned in 2009(link:https://bugs.chromium.org/p/chromium/issues/detail?id=26465), and I also face it in 2018!